JP6791124B2 - Separation method of polymer solution and water - Google Patents

Description

The present invention relates to a separation method for separating water from a mixture containing water and a polymer solution containing a polymer and a non-aqueous organic solvent.

When a polymer is produced using a homogeneous catalyst, the metal component in the homogeneous catalyst may remain in the polymer. The metal components remaining in the polymer may cause equipment corrosion for producing the polymer. In addition, the metal components remaining in the polymer react with air, ultraviolet rays, etc. to cause decomposition of the polymer, which may cause process troubles such as abnormal shape of the polymer pellets, and may affect the hue of the polymer. It could have an impact. Further, the metal component remaining in the polymer may increase the hygroscopicity of the polymer and cause quality problems such as contamination of foreign substances derived from the catalyst residue.

In Patent Document 1, by mixing an acid compound, alcohol, and water in a polymer solution, a homogeneous catalyst in the polymer solution is extracted into an aqueous layer, and then the polymer solution is prepared using a centrifuge or the like. It is separated from water and the homogeneous catalyst is removed from the polymer solution. As a method for separating the polymer solution and water, in addition to the method using a centrifuge, a method such as static separation is also known.

In the static separation, the polymer solution and water are separated by utilizing the principle that water having a large specific gravity settles in the vertical direction due to the difference in specific gravity between the polymer solution and water. However, in the static separation, there is a problem that it takes a long time to settle the water and separate the polymer solution, and the productivity of the polymer solution is low. In centrifugal separation, the polymer solution and water are separated by using centrifugal force in addition to the difference in specific gravity between the polymer solution and water, and it is not possible to separate in a shorter time than static separation. Although it is possible, there is a problem that maintenance of the device requires labor and time.

Further, Patent Document 2 describes a method of separating water from a mixed solution of a cyclohexane oxidizing solution and water using a liquid cyclone type separating device, but separation of the polymer solution and water is intended. Not.

Japanese Unexamined Patent Publication No. 2009-91574 Japanese Unexamined Patent Publication No. 11-267405

The present invention has been made in view of the above-mentioned prior art, and an object of the present invention is to provide a method for efficiently separating water from a mixed solution containing a polymer solution and water.

As a result of diligent studies to solve the above problems, the present inventors have determined the viscosity of the polymer solution in a separation method for separating water from a mixture containing the polymer solution and water using a liquid cyclone type separator. It was found that the above-mentioned problems could be solved by setting the specific range, and the present invention was completed based on this finding.

The gist of the present invention for solving the above problems is as follows.
[1] A separation method for separating water from a mixture containing water and a polymer solution containing a polymer and a non-aqueous organic solvent.
The viscosity of the polymer solution is 300 mPa · s or more and 100,000 mPa · s or less.
A separation method in which the mixed solution is introduced into a liquid cyclone type separating device to separate water from the mixed solution.

[2] The liquid cyclone type separating device includes a hollow cylindrical portion and a hollow conical portion under the cylindrical portion.
The cylindrical portion includes a carry-in path for introducing the mixed solution into the liquid cyclone type separating device, and a recovery port for collecting the polymer solution separated from the mixed solution.
The separation method according to [1], wherein the conical portion is provided with a discharge port for discharging water separated from the mixed liquid at a reduced diameter lower tip.

[3] The separation method according to [1] or [2], wherein the polymer concentration of the polymer solution is 10% by mass or more and 60% by mass or less.

[4] The separation method according to any one of [1] to [3], wherein the polymer is a diene-based polymer and / or an aromatic vinyl-based polymer.

[5] The separation method according to any one of [1] to [4], wherein the speed at which the mixed solution is introduced into the liquid cyclone type separation device is 0.1 m / s or more.

[6] The separation method according to any one of [1] to [5], wherein a plurality of the liquid cyclone type separation devices are arranged and used in series.

According to the separation method according to the present invention, water can be efficiently separated from the mixed solution containing the polymer solution and water by setting the viscosity of the polymer solution within a specific range by using a liquid cyclone type separation device.

The perspective view of the liquid cyclone type separation apparatus in this invention is shown. A schematic cross-sectional view of the liquid cyclone type separator shown in FIG. 1 when cut along the line AA is shown. A schematic cross-sectional view of the liquid cyclone type separator shown in FIG. 1 cut along the line BB is shown. A configuration diagram in which a plurality of liquid cyclone type separators in the present invention are arranged in series is shown.

The separation method according to the present invention is a separation method for separating water from a mixture of a polymer solution containing a polymer and a non-aqueous organic solvent and water, and the viscosity of the polymer solution is 300 mPa · s or more. It is 100,000 mPa · s or less, and the mixed solution is introduced into a liquid cyclone type separating device to separate water from the mixed solution.

(Polymer solution)
The polymer solution in the present invention contains a polymer and a non-aqueous organic solvent, and the polymer is dissolved in the non-aqueous organic solvent.

The polymer is not particularly limited as long as it is dissolved in a non-aqueous organic solvent, and examples thereof include a diene-based polymer, an aromatic vinyl-based polymer, an acrylic-based polymer, a fluorine-based polymer, and a silicone-based polymer. The polymer in the present invention may be one of these polymers alone or may contain two or more of these polymers. Among these, from the viewpoint of efficiently separating water, the polymer preferably contains a diene polymer and / or an aromatic vinyl polymer, and the diene polymer and / or the aromatic vinyl polymer. Is more preferable.

The diene-based polymer is a polymer containing a monomer unit obtained by polymerizing a conjugated diene. The proportion of the monomer unit formed by polymerizing the conjugated diene in the diene polymer is preferably 40% by mass or more, more preferably 50% by mass or more, still more preferably 60% by mass or more in the total monomer unit. Is. In the present invention, the "monomer unit" refers to a structural unit in a polymer formed by polymerizing a monomer.

Diene-based polymers include homopolymers of conjugated diene; copolymers of different types of conjugated diene to each other; copolymers of conjugated diene and other monomers copolymerizable with the conjugated diene; their hydrogens. Additives and the like can be mentioned.

Examples of the conjugated diene include 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1,3-butadiene, 2-ethyl-1,3-butadiene, 2-. Examples thereof include chlor-1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene, and 2,4-hexadiene. Of these, 1,3-butadiene and 2-methyl-1,3-butadiene (isoprene) are preferable.

Other monomers copolymerizable with conjugated diene include α, β-unsaturated nitrile compounds such as (meth) acrylonitrile, α-chloroacrylonitrile, and α-ethylacrylonitrile; (meth) acrylic acid, itaconic acid, and fumal. Unsaturated carboxylic acids such as acids; styrene, chlorostyrene, vinyltoluene, t-butylstyrene, vinylbenzoic acid, methyl vinylbenzoate, vinylnaphthalene, chloromethylstyrene, hydroxymethylstyrene, α-methylstyrene, divinylbenzene, etc. Aromatic vinyl monomer; olefins such as ethylene and propylene; halogen atom-containing monomer such as vinyl chloride and vinylidene chloride; vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl benzoate; methyl vinyl ether , Vinyl ethers such as ethyl vinyl ether and butyl vinyl ether; vinyl ketones such as methyl vinyl ketone, ethyl vinyl ketone, butyl vinyl ketone, hexyl vinyl ketone and isopropenyl vinyl ketone; heterocycles such as N-vinylpyrrolidone, vinylpyridine and vinylimidazole. Vinyl compound contained; (meth) acryloacid ester compound such as methyl (meth) acrylate; hydroxyalkyl group-containing compound such as β-hydroxyethyl (meth) acrylate; (meth) acrylamide, N-methylol (meth) acrylamide, acrylamide Examples thereof include amide-based monomers such as -2-methylpropanesulfonic acid. Among these, aromatic vinyl monomers are preferable, and styrene is more preferable. As the conjugated diene and other monomers copolymerizable with the conjugated diene, one type may be used alone, or two or more types may be used in combination at an arbitrary ratio. Also, as used herein, (meth) acrylic includes both acrylic and methacrylic.

The aromatic vinyl-based polymer is a polymer containing a monomer unit obtained by polymerizing aromatic vinyl. The proportion of the monomer unit formed by polymerizing the aromatic vinyl in the aromatic vinyl polymer is preferably 60% by mass or more, more preferably 70% by mass or more, and further preferably 80 in the total monomer unit. It is mass% or more.

As the aromatic vinyl-based polymer, a homopolymer of aromatic vinyl; a copolymer of different types of aromatic vinyls; a copolymer of aromatic vinyl and another monomer copolymerizable with the aromatic vinyl. Polymers; examples thereof include hydrogenated products thereof.

Examples of aromatic vinyl include styrene, α-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2-ethylstyrene, 3-ethylstyrene, 4-ethylstyrene, and 2,4-diisopropyl. Styrene, 2,4-dimethylstyrene, 4-t-butylstyrene, 5-t-butyl-2-methylstyrene, 2-chlorostyrene, 3-chlorostyrene, 4-chlorostyrene, 4-bromostyrene, 2-methyl Examples thereof include -4,6-dichlorostyrene, 2,4-dibromostyrene and vinylnaphthalene.

Other monomers copolymerizable with aromatic vinyl include conjugated dienes such as 1,3-butadiene, isoprene (2-methyl-1,3-butadiene); (meth) acrylonitrile, α-chloroacrylonitrile, α. -Α, β-unsaturated nitrile compounds such as ethyl acrylonitrile; unsaturated carboxylic acids such as (meth) acrylic acid, itaconic acid and fumaric acid; or acid anhydrides thereof; olefins such as ethylene and propylene; unsaturated carboxylic acids Ester monomer; and the like. As the aromatic vinyl and other monomers copolymerizable with the aromatic vinyl, one type may be used alone, or two or more types may be used in combination at any ratio.

Specific examples of the diene polymer and aromatic vinyl polymer as described above include polybutadiene rubber (BR), styrene / butadiene copolymer rubber (SBR), styrene / isoprene copolymer rubber (SIR), and styrene / isoprene. -Butadiene copolymer rubber (SIBR), styrene-butadiene-styrene block copolymer (SBS), styrene-ethylene-butadiene-styrene block copolymer (SEBS), styrene-isoprene-styrene block copolymer (SIS), Examples thereof include styrene / ethylene / propylene / styrene block copolymer (SEPS). Among these, polybutadiene rubber (BR), styrene / butadiene copolymer rubber (SBR), styrene / isoprene / butadiene copolymer rubber (SIBR), and styrene / isoprene / styrene block copolymer (SIS) are preferable. These polymers can be used alone or in combination of two or more.

The acrylic polymer is a polymer containing a monomer unit derived from a compound represented by the following general formula (1) (hereinafter, may be referred to as "(meth) acrylic acid ester compound").
CH ₂ = CR ¹ −COOR ² (1)
(In the formula, R ¹ represents a hydrogen atom or a methyl group, and R ² represents an alkyl group or a cycloalkyl group.)

The proportion of the monomer unit derived from the (meth) acrylic acid ester compound in the acrylic polymer is preferably 40% by mass or more, more preferably 50% by mass or more, still more preferably 60% by mass, based on all the monomer units. % Or more.

Specific examples of the (meth) acrylic acid ester compound include ethyl (meth) acrylic acid, propyl (meth) acrylic acid, isopropyl (meth) acrylic acid, n-butyl (meth) acrylic acid, and isobutyl (meth) acrylic acid. T-butyl (meth) acrylate, n-amyl (meth) acrylate, isoamyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, Examples thereof include stearyl acrylate.

Acrylic-based polymers include homopolymers of (meth) acrylic acid ester compounds; copolymers of different types of (meth) acrylic acid ester compounds; (meth) acrylic acid ester compounds and (meth) acrylic acid esters. Copolymers with other monomers copolymerizable with the compound; and the like.

Other monomers copolymerizable with the (meth) acrylic acid ester compound include α, β-unsaturated nitrile compounds such as (meth) acrylonitrile, α-chloroacrylonitrile, and α-ethylacrylonitrile; (meth) acrylic acid. , Itaconic acid, unsaturated carboxylic acids such as fumaric acid; having two or more carbon-carbon double bonds such as ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, trimethylpropantri (meth) acrylate. Carboxylate esters; unsaturated esters containing fluorine in the side chain such as perfluorooctylethyl (meth) acrylate; styrene, chlorostyrene, vinyltoluene, t-butylstyrene, vinyl benzoic acid, methyl vinyl benzoate, vinyl Aromatic vinyl monomers such as naphthalene, chloromethylstyrene, hydroxymethylstyrene, α-methylstyrene, divinylbenzene; amides such as (meth) acrylamide, N-methylol (meth) acrylamide, and acrylamide-2-methylpropanesulfonic acid. System monomers: Olefins such as ethylene and propylene; Diene monomers such as butadiene and isoprene; Halogen atom-containing monomers such as vinyl chloride and vinylidene chloride; Vinyl acetate, vinyl propionate, vinyl butyrate, benzoic acid Vinyl esters such as vinyl; Vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, and butyl vinyl ether; Vinyl ketones such as methyl vinyl ketone, ethyl vinyl ketone, butyl vinyl ketone, hexyl vinyl ketone, and isopropenyl vinyl ketone; N-vinylpyrrolidone, Examples thereof include heterocyclic-containing vinyl compounds such as vinylpyridine and vinylimidazole; glycidyl ethers such as allyl glycidyl ether; and glycidyl esters such as glycidyl (meth) acrylate. As the compound represented by the general formula (1) and the other monomer copolymerizable with the (meth) acrylic acid ester compound, one type may be used alone, or two or more types may be arbitrarily used. It may be combined in a ratio.

Specific examples of the acrylic polymer include butyl acrylate polymer, butyl acrylate / allylglycidyl ether copolymer, butyl acrylate / trimethylolpropane (meth) acrylate copolymer, methacrylate / butylaclate copolymer, and methoxyethyl. Examples thereof include acrylate / butyl acrylate copolymers, methyl acrylate / ethylene copolymers, and butyl acrylate / ethylene copolymers. These polymers can be used alone or in combination of two or more.

The fluorine-based polymer is a polymer containing a monomer unit obtained by polymerizing a fluorine atom-containing monomer. The proportion of the monomer unit obtained by polymerizing the fluorine atom-containing monomer in the fluorine-based polymer is preferably 70% by mass or more, more preferably 80% by mass or more, based on all the monomer units.

As the fluorine-based polymer, a homopolymer of a fluorine atom-containing monomer; a copolymer of different types of fluorine atom-containing monomers; a copolymer of a fluorine atom-containing monomer and a fluorine atom-containing monomer. Copolymers with other possible monomers; and the like.

Examples of the fluorine atom-containing monomer include vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, vinyl trifluoride chloride, vinyl fluoride, and perfluoroalkyl vinyl ether.

Other monomers copolymerizable with the fluorine atom-containing monomer include olefins such as ethylene, propylene and 1-butene; styrene, α-methylstyrene, t-butylstyrene, vinyltoluene, chlorostyrene and the like. Aromatic vinyl monomers; α, β-unsaturated nitrile compounds such as (meth) acrylonitrile; (meth) acrylics such as methyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate Acid ester compounds; amide-based monomers such as (meth) acrylamide, N-methylol (meth) acrylamide, N-butoxymethyl (meth) acrylamide; (meth) acrylic acid, itaconic acid, fumaric acid, crotonic acid, maleic acid Unsaturated carboxylic acids such as; epoxy group-containing unsaturated compounds such as allyl glycidyl ether and glycidyl (meth) acrylate; amino group-containing unsaturated compounds such as (meth) acrylic dimethylaminoethyl and (meth) acrylic acid diethylaminoethyl; Sulfonic acid group-containing unsaturated compounds such as styrene sulfonic acid, vinyl sulfonic acid and (meth) allyl sulfonic acid; sulfate group-containing unsaturated compounds such as 3-allyloxy-2-hydroxypropane sulfate; (meth) acrylic acid-3- Examples include phosphoric acid group-containing unsaturated compounds such as propyl chloro-2-phosphate and 3-allyloxy-2-hydroxypropane phosphoric acid. As the fluorine atom-containing monomer and other monomers copolymerizable with the fluorine atom-containing monomer, one type may be used alone, or two or more types may be combined at an arbitrary ratio. Good.

Specific examples of the fluoropolymer include polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinylidene fluoride-hexafluoropropylene copolymer, tetrafluoroethylene-hexafluoropropylene copolymer (FEP), and the like. Examples thereof include polyvinylidene fluoride and tetrafluoroethylene-perfluoroalkyl vinyl ether copolymers. These polymers can be used alone or in combination of two or more.

The silicone-based polymer is a silicone rubber, a fluorosilicone rubber, a polyimide silicone, or the like.

The weight average molecular weight (Mw) of the polymer is not particularly limited, but is a polystyrene-equivalent weight average molecular weight measured by gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent, preferably 30,000. ~ 2,000,000, more preferably 100,000-550,000.

The molecular weight distribution (Mw / Mn) of the polymer is not particularly limited, but is preferably 3.0 or less, more preferably 2.8 or less, and particularly preferably 2.0 or less. The molecular weight distribution (Mw / Mn) of the polymer is a polystyrene-equivalent number average molecular weight (Mn) measured by gel permeation chromatography (GPC) using THF as a solvent, and is the weight average molecular weight (Mw). It is the divided value (Mw / Mn).

In the polymer solution of the present invention, one kind alone or two or more kinds of the above-mentioned polymers may be dissolved in a non-aqueous organic solvent.

The non-aqueous organic solvent is not particularly limited as long as it dissolves the above polymer. The non-aqueous organic solvent means an organic solvent that is substantially insoluble in water. Specific examples of non-aqueous organic solvents include butane, pentane, hexane, heptane, cyclopentane, cyclohexane, methylcyclohexane, dimethylcyclohexane, trimethylcyclohexane, ethylcyclohexane, diethylcyclohexane, decahydronaphthalene, bicycloheptan, tricyclodecane, and hexa. Saturated hydrocarbons such as hydrohexanecyclohexane and cyclooctane; unsaturated hydrocarbons such as 1-butene, 2-butene, 1-pentene and 2-pentene; aromatic hydrocarbons such as benzene, toluene and xylene; chloroform, dichloromethane, Halogen-containing hydrocarbons such as chlorobenzene and dichlorobenzene; propylene glycol; and the like can be mentioned. Among these, unsaturated hydrocarbons, saturated hydrocarbons and aromatic hydrocarbons are preferable, and saturated hydrocarbons are more preferable. The above-mentioned non-aqueous organic solvent may be used alone or in combination of two or more.

As the polymerization reaction for obtaining the polymer solution, any of radical polymerization, anionic polymerization, cationic polymerization, coordination anionic polymerization, coordination cationic polymerization, living polymerization and the like may be used. Examples of the living polymerization include living anionic polymerization, living cationic polymerization, living radical polymerization, living coordination polymerization (including pseudo-living) and the like. From the viewpoint of controlling the weight average molecular weight and structure of the obtained polymer and facilitating the polymerization operation, the polymerization reaction by living polymerization is preferable, and the polymerization reaction by living coordination polymerization including pseudo-living and living anionic polymerization is more preferable.

The polymer solution can be obtained by polymerizing the monomer for obtaining the polymer in a non-aqueous organic solvent using a homogeneous catalyst. The polymerization temperature is usually 0 to 150 ° C., preferably 10 to 100 ° C., particularly preferably 20 to 80 ° C. The polymerization reaction form may be any of solution polymerization, slurry polymerization and the like, but the heat of reaction can be easily removed by using solution polymerization. As the polymerization mode, any of a batch type, a continuous type and the like can be adopted.

The homogeneous catalyst is not particularly limited. The homogeneous catalyst is a catalyst that dissolves in a non-aqueous organic solvent. Specific examples thereof include organic alkali metal compounds; organic alkaline earth metal compounds; homogeneous catalysts mainly using lanthanum series metal compounds; cyclopentadienyl titanium compounds; and diethylaluminum chloride-cobalt type, trialkylaluminum. -Chigler-based catalysts such as boron trifluoride-nickel-based and diethylaluminum chloride-nickel-based;

Examples of the organic alkali metal compound include organic monolithium compounds such as n-butyllithium, sec-butyllithium, t-butyllithium, hexyllithium, phenyllithium, and stillbenzylene; dilithiomethane, 1,4-dilithiobutane, 1,4. -Organic polyvalent lithium compounds such as -dilithio-2-ethylcyclohexane, 1,3,5-trilithiobenzene, 1,3,5-tris (lithiomethyl) benzene; organic sodium compounds such as sodium naphthalene; organic such as potassium naphthalene Potassium compounds; and the like.

Examples of the organic alkaline earth metal compound include din-butylmagnesium, din-hexylmagnesium, diethoxycalcium, calcium distearate, dit-butoxystrontium, diethoxybarium, diisopropoxybarium, and diethyl. Examples thereof include mercaptobarium, dit-butoxybarium, diphenoxybarium, diethylaminobarium, barium distearate, and diketylbarium.

Examples of the homogeneous catalyst using a lanthanum-series metal compound as a main catalyst include lanthanum-series metals such as lanthanum, cerium, placeodim, neodym, samarium, and gadrinium, and lanthanum-series metals composed of carboxylic acids and phosphorus-containing organic acids. Examples thereof include a homogeneous catalyst composed of the salt of the above as a main catalyst and an auxiliary catalyst such as an alkylaluminum compound, an organoaluminum hydride compound, and an organoaluminum halide compound.

Examples of the cyclopentadienyl titanium compound include a cyclopentadienyl titanium halogen compound, a cyclopentadienyl (alkoxy) titanium halogen compound, a bis (cyclopentadienyl) titanium dihalogen compound, and a bis (cyclopentadienyl) titanium dialkyl. Examples thereof include compounds, bis (cyclopentadienyl) titanium diallyl compounds and bis (cyclopentadienyl) titanium dialkoxy compounds. The cyclopentadienyl titanium compound can be mixed with a reducing agent or used alone without a reducing agent.

Examples of the reducing agent used in combination with the cyclopentadienyl titanium compound include various organic alkali metal compounds such as an organic alkylaluminum compound, an organic alkylmagnesium compound, an organic lithium compound, and an organic alkali metal hydride.

The organic alkali metal compound is used as an organic alkali metal amide compound by reacting with a secondary amine such as dibutylamine, dihexylamine, dibenzylamine, pyrrolidine, hexamethyleneimine, and heptamethyleneimine in advance. May be good. One of these homogeneous catalysts may be used alone, or two or more of them may be used in combination.

The amount of the homogeneous catalyst used may be determined according to the molecular weight of the target polymer, but is usually 1 to 50 mmol, preferably 1.5 to 20 mmol, and more preferably 2 per 1000 g of the monomer. It is in the range of ~ 15 mmol.

Further, when a block copolymer is obtained as a diene polymer or an aromatic vinyl polymer, in order to prevent the chain of only one component of the monomer units constituting the block copolymer from becoming long. In addition, a randomizer or the like can be used. In particular, when the polymerization reaction is carried out by anionic polymerization, it is preferable to use a Lewis base compound as a randomizer.

Examples of the Lewis base compound include ether compounds such as dimethyl ether, diethyl ether, diisopropyl ether, dibutyl ether, tetrahydrofuran, diphenyl ether, ethylene glycol diethyl ether and ethylene glycol methyl phenyl ether; and the first such as tetramethylethylenediamine, trimethylamine, triethylamine and pyridine. Examples thereof include tertiary amine compounds; alkali metal alkoxide compounds such as potassium-t-amyl oxide and potassium-t-butyl oxide; phosphine compounds such as triphenylphosphine; and the like. Each of these Lewis base compounds may be used alone, or two or more kinds may be used in combination.

The viscosity of the polymer solution is 300 mPa · s or more and 100,000 mPa · s or less. If the viscosity of the polymer solution is less than 300 mPa · s, the water separated from the mixed solution may be mixed into the polymer solution again. If the viscosity of the polymer solution exceeds 100,000 mPa · s, it is not possible to efficiently introduce the mixed solution containing the polymer solution and water into the liquid cyclone type separator, and it is difficult to separate water from the mixed solution. Is. By setting the viscosity of the polymer solution in the above range, the mixed solution can be efficiently introduced into the liquid cyclone type separator. As a result, the productivity of the polymer solution is increased. From this point of view, the viscosity of the polymer solution is preferably 500 mPa · s or more, preferably 70,000 mPa · s or less, more preferably 40,000 mPa · s or less, still more preferably 20,000 mPa · s or less. Particularly preferably, it is 15,000 mPa · s or less. The viscosity of the polymer solution can be adjusted by the weight average molecular weight (Mw) of the polymer and the polymer concentration described later. The viscosity of the polymer solution is a value measured at 25 ° C. and a rotation speed of 100 rpm using a B-type viscometer.

The polymer concentration of the polymer solution is preferably 10% by mass or more, more preferably 15% by mass or more, further preferably 20% by mass or more, particularly preferably 25% by mass or more, and preferably 60% by mass or less. It is preferably 50% by mass or less, more preferably 45% by mass or less, and particularly preferably 40% by mass or less. According to the separation method according to the present invention, when the polymer concentration is in the above range, both the productivity of the polymer and the separation of the polymer solution and water can be achieved at the same time.

(Mixture)
The mixed solution in the present invention contains the above-mentioned polymer solution and water. Examples of water include distilled water and deionized water.

The mixed solution is obtained by mixing the polymer solution and water. By mixing the polymer solution and water, the metal component derived from the homogeneous catalyst remaining in the polymer dissolves in water. Then, the homogeneous catalyst is removed from the polymer solution by separating the polymer solution and water. The method of mixing the polymer solution and water is not particularly limited, and examples thereof include a method using a mixing device such as a stirring type, a shaking type, and a rotary type. Further, a method using a dispersion kneader such as a homogenizer, a ball mill, a sand mill, a roll mill, a planetary mixer and a planetary kneader can be mentioned.

The amount of water added to the polymer solution is not particularly limited, but is preferably 5% by mass or more, more preferably 10% by mass, from the viewpoint of efficiently dissolving the metal component derived from the homogeneous catalyst remaining in the polymer in water. % Or more, more preferably 15% by mass or more, preferably 300% by mass or less, more preferably 100% by mass or less, still more preferably 50% by mass or less.

The time for mixing the polymer solution and water is not particularly limited, but is preferably 0.5 to 60 minutes, from the viewpoint of efficiently dissolving the metal component derived from the homogeneous catalyst remaining in the polymer in water. It is preferably 1 to 30 minutes, more preferably 2 to 20 minutes. The temperature at the time of mixing is not particularly limited, but is preferably 10 to 100 ° C, more preferably 20 to 80 ° C, from the viewpoint of efficiently dissolving the homogeneous catalyst in water.

The viscosity of the mixed solution is not particularly limited and is appropriately determined according to the amount of water added to the polymer solution having the above-mentioned predetermined viscosity, but is preferably 100 mPa · s or more, more preferably 300 mPa · s or more, and particularly preferably 500 mPa · s. It is s or more, preferably 70,000 mPa · s or less, more preferably 40,000 mPa · s or less, and particularly preferably 20,000 mPa · s or less. The polymer concentration of the mixed solution is not particularly limited and is appropriately determined according to the amount of water added to the polymer solution having the above-mentioned predetermined polymer concentration, but is preferably 5% by mass or more, more preferably 10% by mass. % Or more, particularly preferably 15% by mass or more, preferably 60% by mass or less, more preferably 55% by mass or less, and particularly preferably 45% by mass or less.

(Liquid cyclone type separator)
The liquid cyclone type separation device is a device that separates a polymer solution and water by using centrifugal force by introducing a mixed solution into the inside and swirling the mixed solution. Since the structure of the liquid cyclone type separator is simpler than that of the centrifuge, the maintenance of the apparatus is easy.

Specifically, as shown in FIG. 1, the liquid cyclone type separating device 1 includes a hollow cylindrical portion 10 and a hollow conical portion 20 under the cylindrical portion 10, and the cylindrical portion 10 is a mixed solution. The conical portion 20 is provided with a carry-in path 11 for introducing the liquid into the liquid cyclone type separator 1 and a recovery port 12 for collecting the polymer solution separated from the mixed solution, and the conical portion 20 is separated from the mixed solution at the reduced diameter lower tip. The discharge port 21 for discharging the discharged water is provided.

The mixture containing the polymer solution and water is pressurized by a pump (not shown) and supplied from the carry-in path 11 into the cylindrical portion 10. As shown in FIG. 2, the mixed solution descends while swirling along the inner wall of the cylindrical portion 10 and the inner wall of the conical portion 20. At this time, water having a higher specific gravity than the polymer solution is pressed against the inner wall side of the cylindrical portion 10 and the conical portion 20 by centrifugal force, is accumulated while descending along the inner wall, and is discharged from the discharge port 21. .. On the other hand, the polymer solution having a specific gravity smaller than that of water is accumulated while rotating near the center of the cylindrical portion 10 and the conical portion 20, and turns upward at the lower part of the conical portion 20, and the cylindrical portion 10 and the conical portion 20 are formed. Ascends while turning along the central axis of the above, and is discharged from the collection port 12. In this way, the polymer solution and water are separated.

The speed (introduction speed) of introducing the mixed solution into the liquid cyclone type separator is preferably 0.1 m / s or more, more preferably 0.3 m / s or more, still more preferably 0.6 m / s or more. .. The upper limit of the introduction speed is not particularly limited, but is preferably 10 m / s or less. By setting the introduction rate within the above range, the polymer solution and water can be separated more efficiently, so that the productivity of the polymer solution is excellent. The introduction speed can be calculated from the "flow rate of the mixed liquid" and the "cross-sectional area of the carry-in path 11" (introduction speed = flow rate / cross-sectional area). The cross-sectional area of the carry-in port 11 is not particularly limited, and the introduction speed may be appropriately determined so as to be within the above range according to the flow rate of the mixed liquid. As shown in FIG. 3, when the inner diameter of the carry-in path 11 becomes smaller in the introduction direction of the mixed liquid, the cross-sectional area of the portion having the smallest inner diameter is defined as the “cross-sectional area of the carry-in path 11”. ..

In the liquid cyclone type separator, the relationship between the height H of the conical portion 20, the maximum diameter d1 of the inner diameter of the conical portion 20, and the minimum diameter d2 of the inner diameter of the conical portion 20 shown in FIG. 3 is the following equation (2). ) And the formula (3) are preferable.
H / d1 = 1.5 to 5.0 (2)
d1 / d2 = 3.0 to 10.0 (3)

Further, as shown in FIG. 3, it is preferable that the inner diameter of the carry-in path 11 decreases in the introduction direction of the mixed liquid. In this case, the relationship between the maximum diameter d3 and the minimum diameter d4 of the inner diameter of the carry-in path 11 is preferably expressed by the following equation (4).
d3 / d4 = 1.5 to 5.0 (4)

According to the liquid cyclone type separator having a structure satisfying the relationship of the above formula (2), formula (3) or formula (4), the polymer solution and water can be separated more efficiently, so that the weight is heavy. Excellent productivity of coalesced solution. From this point of view, the preferable range of the numerical range of the formula (2) is 1.8 to 4.0, and the more preferable range is 2.0 to 3.0. The preferable range of the numerical value range of the formula (3) is 5.0 to 9.0, and the more preferable range is 6.0 to 7.0. The preferable range of the numerical value range of the formula (4) is 2.0 to 4.0, and the more preferable range is 2.5 to 3.5.

Further, in the separation method according to the present invention, it is preferable to use a plurality of liquid cyclone type separation devices 1 arranged in series. Further, the mixed solution can be separated by circulating it in a liquid cyclone type separating device, but from the viewpoint of productivity, it is preferable to separate the mixed solution without circulating it in the liquid cyclone type separating device. Specifically, it is arranged so as to connect the collection port of the liquid cyclone type separator and the carry-in path of another liquid cyclone type separator. As shown in FIG. 4, the collection port of the liquid cyclone type separation device and the carry-in path of another liquid cyclone type separation device may be arranged so as to be connected via the valve 100. By arranging the liquid cyclone type separating device in this way, water can be removed from the mixed solution more efficiently. The number of liquid cyclone type separators arranged is one or more, preferably two or more, and more preferably three or more. The upper limit of the number of liquid cyclone type separators arranged is not particularly limited, but is preferably 20 or less.

Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited thereto. Unless otherwise specified, parts and% in this embodiment are based on mass.

<Viscosity of polymer solution>
The viscosity of the polymer solution was measured using a B-type viscometer (“Digital Viscometer DV-II + Pro”, manufactured by Brookfield) under the conditions of a temperature of 25 ° C. and a rotation speed of 100 rpm.

<Manufacturing of polymer solution>
Polymer solution 1
Using a pressure-resistant reactor, 122 parts of cyclohexane, 0.0012 parts of N, N, N', N'-tetramethylethylenediamine (TMEDA) and 9.6 parts of styrene were stirred at 40 ° C. As a result, 0.0434 parts of n-butyllithium was added and polymerized for 1 hour while raising the polymerization temperature to 50 ° C. to obtain a polystyrene block polymer. At this point, the polymerization conversion rate of styrene was 100%.

A part of the reaction solution was sampled, and the weight average molecular weight of the polystyrene block polymer was measured by gel permeation chromatography measurement. The weight average molecular weight of the polystyrene block polymer was 15.8 × 10 ^3. The weight average molecular weight was measured by high performance liquid gel permeation chromatography using tetrahydrofuran as a carrier and converted into polystyrene.

Subsequently, 38.4 parts of isoprene was added over 1 hour while controlling the temperature so that the reaction temperature was between 50 ° C. and 60 ° C., and after the addition was completed, the mixture was polymerized for another 1 hour to obtain a styrene-isoprene block copolymer. Got The polymerization conversion rate of isoprene at this point was 100%. A part of the reaction mixture was collected, by gel permeation chromatography, styrene - isoprene diblock copolymer where the weight average molecular weight of (. Which (b) and component) was measured at 92 × 10 ³ there were.

Next, 0.0073 parts of dimethyldichlorosilane was added as a coupling agent and the coupling reaction was carried out for 2 hours to form a styrene-isoprene-styrene triblock copolymer (used as component (a)) to form the polymer. Solution 1 was obtained. The polymer concentration of the polymer solution 1 was 28.2%, and the viscosity of the polymer solution 1 was 3700 mPa · s. In Table 1, the styrene-isoprene-styrene triblock copolymer is referred to as "SIS".

When a part of the reaction solution was sampled and subjected to gel permeation chromatography measurement, the styrene unit content in the triblock copolymer was 20%, and the weight average molecular weight of the component (a) was 174 ×. 10 ^3, (a) component and the component (b) weight ratio of 6: 4. The ratio of the component (a) to the component (b) was determined from the peak area of each copolymer obtained by high performance liquid gel permeation chromatography.

Polymer solution 2
Two stainless steel polymerization reactors equipped with a stirrer, a cooling jacket and a reflux condenser were connected in series, and continuous polymerization was carried out as follows.

A 1,3-butadiene solution containing 11% toluene, 40% cis-2-butene, 9% trans-2-butane, 6% other non-aqueous organic solvents such as n-butane and 34% 1,3-butadiene. While flowing through the pipe at a flow rate of 70 kg / h, 1,2-butadiene as a molecular weight adjuster was added at 800 mmol per hour, trimethyl orthorate as an inhibitor of gelation was added at 5 mmol per hour, and 2.5 g of water was added per hour to disperse. And a dispersion was obtained. Water was added after passing through a stainless steel sintered filter having a pore size of 2 microns.

To this dispersion was further added 350 mmol / h (as a toluene solution) of diethylaluminum monochromeide, which was introduced into the polymerization reactor. A solution of high cis polybutadiene was obtained by adding 28 g of a 3% cobalt octene acid toluene solution per hour to a polymerization reactor from another pipe and performing continuous polymerization at 20 ° C. and a residence time of 2 hours for 120 hours.

A solution of high cis polybutadiene was continuously withdrawn from the second polymerization reactor using a transfer pump. When extracting, add 360 g of methanol as a polymerization inhibitor from the suction side of the transfer pump in the form of a 10% toluene solution per hour, and further stir and mix with a static mixer (6 elements) connected to the discharge side of the pump. The polymerization reaction was stopped. The polymerization conversion rate at this time was 65%.

This was introduced into a steam stripping container. In a steam stripping container, the ratio of 1000 parts of water, 180 parts of steam (temperature 240 ° C., pressure 1020 kPa), and 0.8 parts of 10% aqueous sodium hydroxide solution to 100 parts of high cis-polybutadiene produced by polymerization. Introduced in. The temperature inside the container was 105 ° C., the pressure inside the container was 320 kPa, and the average residence time was 30 minutes. In this step, unreacted 1,3-butadiene and a non-aqueous organic solvent were removed, and high cispolybutadiene dispersed in water in a crumb form was obtained. A dispersion in which high cis polybutadiene was dispersed in water in a crumb shape was continuously withdrawn from a steam stripping container. This dispersion was squeezed by hand to obtain a crumb with a water content of 20%. The obtained crumb was dried with hot air at 80 ° C. for 1 hour to obtain a high cispolybutadiene having a moisture content of 0.1%. The obtained high cis polybutadiene had a weight average molecular weight (Mw) of 430,000 and a molecular weight distribution (Mw / Mn) of 2.8 as measured by gel permeation chromatography. The cis ratio of this high cis polybutadiene in the butadiene unit, which was determined from ¹³ C-NMR spectrum measurement, was 97.2%. 100 parts of this high cis polybutadiene was dissolved in 585 parts of cyclohexane to obtain a polymer solution 2 of polybutadiene rubber (BR). The polymer concentration of the polymer solution 2 was 14.6%, and the viscosity of the polymer solution 2 was 6,000 mPa · s.

Polymer solution 3
Under a nitrogen atmosphere, 1890 g of n-hexane, 810 g of cyclohexane, and 500 g of 1,3-butadiene were charged in an autoclave, 6.5 mmol of n-butyllithium was added, and polymerization was started at 50 ° C. From 30 minutes after the start of polymerization to 30 minutes, 500 g of 1,3-butadiene was continuously added. Then, the polymerization reaction was continued for 30 minutes, and after confirming that the polymerization conversion rate became about 100%, 2.5 mmol of tin tetrachloride was added and reacted for 15 minutes, followed by N- as a denaturant. 4.5 mmol of methyl-2-pyrrolidone was added and the reaction was carried out for 10 minutes. Then, 12 mmol of methanol was added as a polymerization terminator to obtain a polymer solution 3 of polybutadiene rubber (BR). The polymer concentration of the polymer solution 3 was 27%, and the viscosity of the polymer solution 3 was 55,000 mPa · s.

When a part of the reaction solution was sampled and subjected to gel permeation chromatography measurement, the weight average molecular weight (Mw) of the polymer was 539,000 and the molecular weight distribution (Mw / Mn) was 1.7. It was. The vinyl bond content in the butadiene unit of this polybutadiene rubber was 9 mol%. The microstructure of the polybutadiene rubber was measured by ¹ H-NMR (measuring instrument: manufactured by JEOL Ltd., trade name "JNM-ECA-400WB", measuring solvent: deuterated chloroform).

(Example 1)
The polymer concentration of the polymer solution 1 was adjusted to 20% by mass, and the viscosity of the polymer solution 1 was adjusted to 710 mPa · s. Specifically, cyclohexane was added to the polymer solution 1 to prepare the mixture. 100 parts by mass and 20 parts by mass of water of the polymer solution 1 prepared in this way were continuously supplied to the mixing tank. Then, it was mixed in a mixing tank using a homomixer (manufactured by PRIMIX) to obtain a mixed solution. The residence time in the mixing tank of the polymer solution 1 and water was 3 minutes, and the rotation speed of the homomixer was 10000 rpm. Then, the mixed solution was received in a storage tank (TK-1 in FIG. 4).

Next, the mixed solution was supplied to the liquid cyclone type separator 1 (NS NEW CYCLONE-Z manufactured by Nihon Spindle Manufacturing Co., Ltd.) at an introduction rate of 1.0 m / s. As shown in FIG. 4, three liquid cyclone type separators 1 were connected in series. At this time, the valve 100 connected to the collection port in the liquid cyclone type separator was opened, and the valve 200 connected to the discharge port was closed. The residence time of the mixed solution in the liquid cyclone type separator was 5 minutes.

After sending out all the mixed solution in TK-1, the valve 200 connected to the discharge port in the liquid cyclone type separator was opened, water was drawn out from the mixed solution, and the mixture was received in the storage tank (TK-2 in FIG. 4). .. Then, the mass of water in TK-2 was measured. From the mass [kg] of water in the mixed solution in TK-1 and the mass [kg] of water extracted into TK-2, the water removal rate [%] was calculated by the following formula.
Water removal rate [%] = (mass of water extracted to TK-2 [kg]) / (mass of water in mixed solution in TK-1 [kg]) × 100

Moreover, the processing speed of the polymer was calculated by the following formula.
Polymer processing rate [kg / h] = (mass of polymer solution in mixed solution in TK-1 [kg]) / (time required to deliver the mixed solution from TK-1 to the liquid cyclone type separator [h] ])

(Examples 2 to 7, Comparative Example 3)
As in Example 1, the water removal rate and the water removal rate and the number of devices arranged in series were changed, except that the polymer solution, the polymer concentration, the viscosity of the polymer solution, the introduction rate, and the number of devices arranged in series were changed as described in Table 1. The polymer processing rate was calculated. In Examples 2 to 5 and Comparative Example 3, the polymer concentration was adjusted by evaporating and concentrating cyclohexane from the polymer solution 1. The introduction speed was adjusted by the flow rate of the mixed solution.
In Comparative Example 3, due to the high viscosity of the polymer solution, the pressure loss in the carry-in path of the liquid cyclone type separator was large (800 kPa or more), and the introduction speed of 0.09 m / s or more could not be obtained. ..

(Comparative Example 1)
The polymer concentration of the polymer solution 1 was adjusted to 30.3% by mass, and the viscosity of the polymer solution 1 was adjusted to 6,000 mPa · s. Specifically, the polymer concentration was adjusted by evaporating and concentrating cyclohexane from the polymer solution 1. 100 parts by mass and 20 parts by mass of water of the polymer solution 1 prepared in this way were continuously supplied to the mixing tank. Then, it was mixed in a mixing tank using a homomixer (manufactured by PRIMIX) to obtain a mixed solution. The residence time in the mixing tank of the polymer solution 1 and water was 3 minutes, and the rotation speed of the homomixer was 10000 rpm.

7500 g of the obtained mixed solution was collected in a container, covered with a lid, and allowed to stand.

After 3 days, the water accumulated at the bottom of the container was taken out and its mass was measured. Then, the water removal rate [%] was calculated from the mass [g] of water in the mixed solution and the mass [g] of water extracted from the container.
Water removal rate [%] = (mass of water extracted from container [g]) / (mass of water in mixed solution in container [g]) x 100

Moreover, the processing speed of the polymer was calculated by the following formula.
Polymer processing rate [kg / h] = (mass [g] of polymer solution in mixed solution in container) / (standing time [h]) / 1000

(Comparative Example 2)
Similar to Comparative Example 1, the polymer concentration of the polymer solution 1 was adjusted to 30.3% by mass, and the viscosity of the polymer solution 1 was adjusted to 6,000 mPa · s. 100 parts by mass and 20 parts by mass of water of the polymer solution 1 prepared in this way were continuously supplied to the mixing tank. Then, it was mixed in a mixing tank using a homomixer (manufactured by PRIMIX) to obtain a mixed solution. The residence time in the mixing tank of the polymer solution 1 and water was 3 minutes, and the rotation speed of the homomixer was 10000 rpm.

50 g of the obtained mixed solution was placed in a centrifuge tube and treated with a centrifuge (H-103NS manufactured by Koksan Co., Ltd.). The rotation speed of the centrifuge was 4000 rpm, and the rotation time was 5 minutes. The water collected at the bottom of the centrifuge tube was extracted and its mass was measured. Then, the water removal rate [%] was calculated from the mass [g] of water in the mixed solution and the mass [g] of water extracted from the centrifuge tube.
Water removal rate [%] = (mass of water extracted from centrifuge tube [g]) / (mass of water in mixed solution in centrifuge tube [g]) × 100

Moreover, the processing speed of the polymer was calculated by the following formula.
Polymer processing rate [kg / h] = (mass of polymer solution in a mixture placed in a centrifuge tube [g]) / (rotation time of centrifuge [h]) / 1000

From Table 1, it can be seen that according to the separation method according to the present invention, the removal rate of water from the mixed solution is high and the polymer treatment rate is excellent.

1: Liquid cyclone type separator 10: Cylindrical part 11: Carry-in path 12: Recovery port 20: Conical part 21: Discharge port

Claims (5)

A separation method for separating water from a mixture of a polymer solution containing a polymer and a non-aqueous organic solvent and water.
The viscosity of the polymer solution is 300 mPa · s or more and 100,000 mPa · s or less.
Including introducing the mixture into a liquid cyclone separator to separate water from the mixture .
The liquid cyclone type separation device includes a hollow cylindrical portion and a hollow conical portion under the cylindrical portion.
The cylindrical portion includes a carry-in path for introducing the mixed solution into the liquid cyclone type separating device, and a recovery port for collecting the polymer solution separated from the mixed solution.
A separation method in which the conical portion is provided with a discharge port for discharging water separated from the mixed liquid at the lower tip having a reduced diameter . The separation method according to claim 1, wherein the polymer concentration of the polymer solution is 10% by mass or more and 60% by mass or less. The separation method according to claim 1 or 2, wherein the polymer is a diene-based polymer and / or an aromatic vinyl-based polymer. The separation method according to any one of claims 1 to 3 , wherein the speed at which the mixed solution is introduced into the liquid cyclone type separation device is 0.1 m / s or more. The separation method according to any one of claims 1 to 4 , wherein a plurality of the liquid cyclone type separation devices are arranged and used in series.

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